This returns an empty document:
#include <mongocxx/client.hpp> #include <bsoncxx/builder/stream/document.hpp> #include <bsoncxx/json.hpp> #include <iostream> using bsoncxx::builder::stream::document; int main(int, char**) { mongocxx::client conn{}; document command; command << "buildInfo" << 1; auto db = conn["test"]; auto result = db.command(command.view()); std::cout << "buildInfo response: " << bsoncxx::to_json(result.view()) << std::endl; return 0; }
(actually it crashes on exception, but that is due to CXX-587)
I tracked this down to missing initialization in scoped_bson_t reply object.
Patch in https://github.com/mongodb/mongo-cxx-driver/pull/284